Lea, T. 2006.Historical Garry Oak Ecosystems of Vancouver Island, British Columbia, pre-European Contact to the Present. Davidsonia 17(2):34-50

This paper summarizes the historical mapping of the major areas of Quercus garryana (Garry oak) ecosystems, from immediate pre-European settlement to present day. Less than 10 percent of the original Garry oak ecosystem remains on south-eastern Vancouver Island, British Columbia, Canada. Originally, there were two major ecosystem types, one on deep soils, known as Parkland Garry oak ecosystems, and the second on shallow soils, often referred to as scrub oak ecosystems because the oak trees are often of low stature. Little of the deep soil ecosystem remains, because these communities were the first areas cleared for agriculture and urban development. More of the shallow soil ecosystem remains, as many of these rocky areas were more difficult to develop in the early days of settlement and were not good for agriculture. However, many of these sites are presently being lost to development if they are not in protected areas. Much of the remaining area of these ecosystems is dominated by invasive alien plant species, so that less than 5 percent of the original area remains in natural condition.